The present disclosure relates to piston pumps, and in particular pumps utilized to apply stripes to ground surfaces, such as roadways, parking lots, and tarmacs.
Ground marking can be accomplished with a polymer-based lines. The polymer-based lines are more durable than conventionally painted lines. In some cases, the polymer-based lines are thermally applied to the ground surface. In other cases, a plasticizing material is mixed with a catalyst prior to application to the ground surface. The catalyst then evaporates, leaving a polymer stripe on the ground surface. The ratio between the catalyst and the plasticizing material must be maintained at a desired level, generally with a much higher level of plasticizing material than catalyst, to ensure that the line has the desired properties, such as thickness, width, reflectivity, color, etc. The plasticizing material and the catalyst are driven by two separate pumps. To maintain the desired ratio the pump driving the catalyst typically has a significantly smaller displacement, and thus smaller component parts, than the other pump. However, the catalyst can cause sticking of the components, such as the springs of the valves within the pumps, thereby causing the catalyst pump to stick in an open state.